Hard surfaces that are washed but not dried often suffer from spotting. In particular, glassware, dishes, and cutlery washed in an automatic dishwasher may develop hard water spots. Such hard water spots are undesirable because they have an undesirable appearance causing the clean objects to appear dirty. To overcome this problem, rinse aids are often used to minimize or hopefully eliminate such spotting.
Some commercially available rinse aids include nanoparticles. Adding nanoparticles to rinse aids provide desirable results in improving sheeting, thus reducing hard water spots. However, incorporating nanoparticles into rinse aids has its drawbacks. While the benefits of including nanoparticles are impressive, the drawbacks may outweigh the advantages. Incorporating nanoparticles into a detergent or rinse aid is expensive. Nanoparticles may be purchased commercially from vendors, but in the detergent and rinse aid market, it is often a prohibitively expensive ingredient. While nanoparticles are sold commercially, their availability is largely limited because many vendors do not sell them nor do many manufacturers manufacture them. Additionally, nanoparticles can be difficult and dangerous to handle. They pose a potential hazard to workers who risk aspirating the minute particles into their respiratory system resulting in serious health problems. Another drawback is that the nanoparticles often clump or agglomerate thus reducing or eliminating their effectiveness. Agglomeration results in particles that are not present in the form of discrete particles, but instead predominantly assume the form of agglomerates due to consolidation of the primary particles. Such agglomerates may reach diameters of several thousand nanometers, such that the desired characteristics associated with the nanoscale nature of the particles cannot be achieved. If agglomeration occurs, an expensive, dangerous to handle ingredient loses its ability to improve sheeting and reduce hard water spots.
It is apparent that there is a continuing need to improve the various properties of all dishware surfaces in automatic dishwashers, including but not limited to glass, plastics, metals, and ceramic surfaces. Such improvement would result in dishware surfaces having one or more of the following highly desirable modified surface properties such as improved wetting and sheeting, uniform drying, anti-spotting, anti-staining, anti-filming, and durability. Desirably, such improvement would provide the benefits of including nanoparticles into the composition yet would exclude all of the drawbacks associated with inclusion of such an ingredient in the composition.